Safety valve unit



llgl1., 1942- c. M. BAILEY ET AL 2,292,426

SAFETY VALVE UNIT Filed Dec. 16, 1940 WWE@ f2 y //Jg INVENTORS yCbaMaiZey BY 0121.1 Turner 0r/11: YW

Patented Aug. 11, 1942 UNITED STATES SAFETY VALVE UNIT Charles M. Baileyand William J. Turner, San Francisco, Calif.

7 Claims.

This invention comprises in general an improvement in safety valves, andin particular the invention is directed to a novel form of safety valveunit primarily designed for use in connection with gas fired Waterheaters and like apparatus.

Domestic hot water heaters are commonly provided with automatictemperature regulators which normally function to maintain the water inthe tank at a predetermined temperature. However, these automaticregulators sometimes fail to function, whereupon the water in the tankreaches boiling point and the resultant steam pressure may cause anexplosion of the heater.

It is therefore the principal object of this invention to provide asafety valve unit adapted to be interposed in the gas feed pipe of awater heater and operative upon occurrence of abnormal pressureconditions in the water tank to shut off the flow of gas through saidpipe.

Another object of the invention is to provide a safety valve unit, asabove, including adjustable means to set the unit to operate at apredetermined abnormal pressure.

A further object of the invention is to provide snap action closing ofthe safety Valve; such snap action movement being effected by suitablemechanism actuated by a pressure responsive element.

It is also an object of the invention to provide a safety valve unitdesigned for ready connection with conventional water heaters.

A further object of the invention is to produce a simple and inexpensivedevice and yet one .which will be exceedingly effective for the purposefor which it is designed.

These objects we accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawing similar characters of reference indicate correspondingparts in the several views:

Figure l is a sectional elevation of the unit illustrating the valveassembly in open position.

Figure 2 is a sectional elevation yof the unit illustrating the valveassembly in closed position.

Referring now more particularly to the characters of reference on thedrawing, the safety valve unit comprises'a body I formed with spacedinternal chambers, indicated at 2 and 3 respectively; such chambersopening to opposite ends of the body and being threaded adjacent theirouter ends for the reception of adjacent ends of the gas feed pipe 4 inwhich the unit is adapted to be interposed.

The unit is interposed in the gas feed line so that the gas flows firstinto chamber 3, and from chamber 3, the gas flows upward through a port3a into an enclosed hood or housing 5. This housing is initially open atthe bottom, but is secured in sealed relation with the top of body I bymeans of a gasket 6 being interposed between the housing and said body.From the housing 5, the gas flows downward through a Valve seat 'I intochamber 2 and thence out into the gas feed pipe in the direction of theburner of the water heater.- y

A disc valve 8 cooperates with valve seat 1 and is carried by valve stem9 which extends through a spider I0 centrally of the valve seat andthrough the bottom of the body below chamber 2. In its normal position,valve 8 is open relative to valve seat 1 as shown in Fig. l.

The lower end of valve stem 9 projects into a downwardly opening socketII formed on the body, and into which socket a plug I2 is threaded;there being an inverted, cup-like flexible diaphragm D secured in thesocket II inwardly of plug I2, whereby to prevent gas from escaping byvalve stem 9 and out of the socket when plug I2 is removed. f

The valve 8 is normally maintained in open position by means of asnap-action toggle link assembly constructed as follows: A pair of rigidposts I3 are mounted in upstanding position on the body within housing5, and on opposite sides of the vertical plane of valve stern 9. A leverI4 is pivoted intermediate its ends as at I5 on the upper end of one ofthe posts I3, for swinging movement in a vertical plane. A compressionspring IB is pivoted at one end on the upper end of the other post I3 asat Il, while the iadjacent ends of lever I4 and compression spring I6are fitted with a pin and cup toggle i8; the lever I4 and spring I6sloping upwardly toward each other when the valve is open. A link I9 ispivotally connected at 2i] to lever I4 adjacent the toggle I8 anddepends therefrom to pivotal connection at 2l with the upper end ofvalve stem 9 `above valve 8.

In order to trip the snap action toggle link assembly downward beyond ahorizontal plane and to a valve closing position, and when abnormalpressure conditions occur in the hot water tank of the water heater, Iprovide the following instrumentalities: The body I between chambers 2and 3 is formed with a passage 22 therethrough; the lower end of saidpassage being threaded for connection with a pipe 23 leading from thetop of the water tank 24 of the water heater. At its upper end, passage22 is threaded for the reception of the lower end of the hollow base 25of a Bourdon tube 26 which extends from the upper end of said base on acurve to a point adjacent but above the snap action toggle linkassembly. From such point, the Bourdon tube is i'itted with a projectingarm 21 which terminates some distance above the end of lever I4 which isopposite toggle I8. A pin 28 projects laterally from lever I4 adjacentsaid end, and rides in a vertically elongated slot 29 in a link 30suspended from the free end of arm 2T by means of an adjustment screw3l.

Operation When the temperature regulator of the water heater isoperating normally, the several elements of the safety valve unit aredisposed in the position shown in Fig. 1. However, should thetemperature regulator fail to function properly and the water be heatedexcessively and steam pressure created, such pressure passes throughpipe 23, base 25 and thence into the Bourdon tube 26. When this occurs,the Bourdon tube expands, causing the free end of arm 21 to rise,carrying with it link 3i] which in turn trips the snap action togglelink assembly downward, causing valve 8 to close with valve seat 1. Thisshuts off the flow of gas in the gas feed pipe 4, and prevents furtherheating of the water in tank 24; thus providing adequate safety againstexplosion of the tank. When the snap action toggle link assembly istripped downward, the pin 28 rides up in slot 29 and no strain is placedon tube 26.

Once the safety valve unit has actuated and the valve closed, it must bemanually reset. This is accomplished by removing plug i 2 and depressingthe inverted cup-like diaphragm D upwardly until the lower end of valvestem 9 is engaged and forced upward, effecting an opening of valve 8from valve seat 1, as well as an upward snap action of the toggle linkassembly, anda return of pin 28 to the lower end of slot 29.

From the foregoing description it will be readily seen that we haveproduced such a device as substantially fullls the objects of theinvention as set forth herein.

While this specication sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as dened by the appended claims.

Having thus described our invention, what we claim as new and useful anddesire to secure by Letters Patent is:

1. A pressure actuated valve unit comprising a body having spacedchambers therein open to the exterior of the body and threaded forreception of ends of pipe, means forming a passage between saidchambers, a normally open valve mounted in said passage, normallyinactive means to close said valve, and other means responsive toabnormal pressure conditions operative to actuate said normally inactivemeans, said rst named means including a housing removably mounted on andenclosing one face of the body, the valve and said normally inactivevalve closing means being outwardly of said face of the body and beingenclosed within the housing.

2. A pressure actuated valve unit including a normally open valve, asnap action toggle link assembly mounted adjacent but spaced from thevalve, a link pivotally connected between the assembly and the valve andarranged to close the valve upon snap action movement of the assembly toone position and to open the valve upon snap active movement of theassembly to another and normal position, a Bourdon tube responsive toabnormal pressure conditions mounted adjacent and means operativelyconnecting said tube and said snap action toggle link assembly, saidtube being operative to effect snap action movement of said assembly tosaid one position, and said means comprising a longitudinally slottedlink depending from the free end of the tube, said end of the tube beingdisposed above the assembly and adjacent one end thereof, thecorresponding lever of the assembly being extended beyond its pivot in adirection away from the assembly and a horizontal pin projecting fromsaid portion of the lever and normally engaging in the bottom of theslot of the link.

3. A pressure actuated valve unit including a normally open valve, meansto close said valve, other means responsive to abnormal pressureconditions operative to actuate said iirst named means, and a manuallyactuated element to open said valve; the valve unit including a body,and said element being a valve stem rigid with the valve and slidablyprojecting through and extending beyond the body, an outwardly openingsocket formed on the body and surrounding and completely enclosing theprojecting portion of the valve stem, and a removable plug in andclosing the outer end of the socket.

4. A pressure actuated valve unit comprising a body having spacedchambers therein open to opposite sides of the body and threaded for thereception of ends of pipe, a housing mounted on and enclosing a portionof the exterior of the said chambers into said housing, a valve mountedon the body and arranged to close one of saidl ports, the valve beingaccessible from within the housing, a normally inactive snap actiontoggle link assembly mounted in the housing in connection with saidvalve and arranged to close the latter, and a Bourdon tube disposedinthe housing and connected with said assembly to actuate the same uponexpansion of the tube, the body having a passage therethrough fromwithin the housing, and the base of the tube being mounted incommunication with the inner end of said passage, the outer end of saidpassage being adapted for connection in communication with a source ofpressure.

5. A pressure actuated valve unit comprising a body having spacedchambers open at one end for connection with pipe ends and having portsopen to one face of the body, a housing removably mounted on`andenclosing said one face and the ports, one port within the housinghaving a surrounding valve seat, a normally open valve to cooperate withsaid seat, normally inactive valve closing means within the housing, andother means in the housing responsive to abnormal pressure conditions toactuate said normally inactive means.

6. A device as in claim 5, including a iiexible cupped airtightdiaphragm disposed in the socket over and clear of the adjacent end ofthe stem and sealed about its periphery in the body inwardly of theplug.

7. A pressure actuated valve unit comprising a body, a housing over andenclosing one face of the body, a pair of longitudinally separatedchambers in the body having their opposite ends Cil said normallyinactive means; the body having a passage therethrough between thechambers and extending to said one face of the body and to which thepressure means is connected.

CHARLES M. BAILEY. WILLIAM J. TURNER.

